Staples have been used to secure bundles of papers together for many years. Almost commensurate with the development of the staple and means for securing same to a bundle, arose the need to remove the secured staple, and initially this need was met through the expedient of fingernails, scissors, etc., none of which proved wholly satisfactory for the task.
Eventually machines were developed expressly for the purpose of removing staples. Initially hand-operated machines were developed, such as those found in U.S. Pat. No. 4,513,951; U.S. Pat No. 2,102,087; Swiss Patent No. 278,608; West German Patent Application No. 1,195,269; and French Patent No. 1,017,105. See also European Patent Application No. 0,022,364. The development of hand-operated machines was followed by automatically operated machines. The automatic machines are typically provided with a gripping means, in which a stapled bundle can be positioned, such that the gripping means can pull the staple out of the positioned bundle. The drawback of such automatic machines, however, is that such machines only operate smoothly when removing staples from bundles stapled at a fixed location relative to the bundle. While such machines may be used with some success in situations where the bundle is stapled automatically at a predetermined location, the same machine will not work well in the case of hand-stapled bundles, in which the staple location is apt to vary widely from one bundle to the next. In order to utilize the automatic staple removing machines for bundles which have been stapled by hand, such machines must be equipped both with a detection system for detecting the location of the staple in the bundle, and with a positioning system for putting the gripping means in the proper position relative to the staple. Such modification results in a complicated and consequently costly device.
There exists a need for a simple device for removing staples from bundles of stapled sheets, for example for removing staples from a stapled bundle of originals, in order to process these originals automatically on a copying machine fitted with an automatic feeding device for the originals.
One such simple device is that shown in European Patent Application No. 0,106,381, which describes a copying machine, the top of which has a cavity in which a strip having a wedge-shaped end is provided, with the top of the strip being situated largely in the same plane as the top of the copying machine. To remove a staple from a stapled bundle using this device, the operator must position the bundle such that the bent legs of the staple face upwards, and must position the staple immediately in front of the wedge-shaped end of the strip. The operator then pulls the bundle towards the strip to remove the staple. Frequently when the bundle is pulled towards the strip, the wedge-shaped end of the strip does not penetrate between the staple and the lowermost sheet, rather rushes past the bundle. Efforts to avoid this result by manually exerting a force on the bundle creates the risk that the bundle may be pressed askew on the wedge-shaped end, which may in turn penetrate the individual sheets of the bundle, damaging the sheets. Damaged sheets in turn can cause malfunctions in the copying operation. Another disadvantage of exerting manual pressure on the bundle is that this allows only one hand (that hand not exerting the pressure) for effecting the pulling movement. As a result, it is difficult to pull the bundle controllably in a straight direction over the strip. Pressing manually on the staple during the pulling sequence has the added disadvantage of creating a risk that the rising ends of the staple may penetrate into the hand and cause injuries.
The object of the present invention is to provide a simple device for removing a staple from a stapled bundle of sheets, which device does not exhibit the drawbacks mentioned above.